Ibacache-Quiroga Claudia, González-Pizarro Karoll, Charifeh Mariam, Canales Christian, Díaz-Viciedo Rodrigo, Schmachtenberg Oliver, Dinamarca M Alejandro
Escuela de Nutrición y Dietética, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile.
Centro de Micro-Bioinnovación, Universidad de Valparaíso, Valparaíso 2360102, Chile.
Foods. 2022 Mar 22;11(7):900. doi: 10.3390/foods11070900.
Kefir beverage is a probiotic food associated with health benefits, containing probiotic microorganisms and biomolecules produced during fermentation. The microbial composition of these beverages varies among countries, geographical regions, and the substrates, therefore, the characterization of kefir beverages is of great relevance in understanding their potential health-promoting and biotechnological applications. Therefore, this study presents the metagenomic and functional characterization of two Chilean kefir beverages, K02 and K03, through shotgun and amplicon-based metagenomic, microbiological, chemical, and biochemical studies. Results show that both beverages’ microbiota were mainly formed by Bacteria (>98%), while Eukarya represented less than 2%. Regarding Bacteria, the most abundant genera were Acetobacter (93.43% in K02 and 80.99% in K03) and Lactobacillus (5.72% in K02 and 16.75% in K03), while Kazachstania was the most abundant genus from Eukarya (42.55% and 36.08% in K02 and K03). Metagenomic analyses revealed metabolic pathways for lactose and casein assimilation, biosynthesis of health-promoting biomolecules, and clusters for antibiotic resistance, quorum sensing communication, and biofilm formation. Enzymatic activities, microbial β-amyloids, and short-chain fatty acids (acetic acid and propionic acid) were also detected in these beverages. Likewise, both kefir beverages inhibited biofilm formation of the opportunistic pathogen Pseudomonas aeruginosa.
开菲尔饮料是一种具有健康益处的益生菌食品，含有益生菌微生物和发酵过程中产生的生物分子。这些饮料的微生物组成因国家、地理区域和底物而异，因此，对开菲尔饮料进行表征对于理解其潜在的健康促进和生物技术应用具有重要意义。因此，本研究通过鸟枪法和基于扩增子的宏基因组学、微生物学、化学和生物化学研究，对两种智利开菲尔饮料K02和K03进行了宏基因组学和功能表征。结果表明，两种饮料的微生物群主要由细菌组成（>98%），而真核生物占比不到2%。在细菌方面，最丰富的属是醋酸杆菌（K02中占93.43%，K03中占80.99%）和乳杆菌（K02中占5.72%，K03中占16.75%），而真核生物中最丰富的属是哈萨克斯坦酵母（K02和K03中分别占42.55%和36.08%）。宏基因组分析揭示了乳糖和酪蛋白同化的代谢途径、促进健康生物分子的生物合成以及抗生素抗性、群体感应通讯和生物膜形成的基因簇。在这些饮料中还检测到了酶活性、微生物β-淀粉样蛋白和短链脂肪酸（乙酸和丙酸）。同样，两种开菲尔饮料都抑制了机会性病原体铜绿假单胞菌的生物膜形成。
